Transient right axis deviation during acute anterior wall infarction or ischemia: electrocardiographic and angiographic correlation.

Eleven patients, three with acute anterior myocardial infarction and eight with anterior ischemia, who developed transient right axis deviation with a left posterior hemiblock pattern during the acute phase of myocardial infarction or ischemia are described (study group). A correlation between their electrocardiographic pattern and the angiographic findings was made. The arteriographic findings were compared with those of a group of 24 patients with acute anterior myocardial infarction or ischemia without transient right axis deviation (control group). The main electrocardiographic characteristics of the right axis deviation pattern were: an average shift of the mean frontal axis to the right of 42 degrees (10 degrees to 94 degrees); increased voltage of R waves in leads II, III and a VF and appearance of small Q waves or decreased voltage of Q waves if previously present in the same leads; decreased voltage of R waves and appearance of deep S waves in lead aVL; and inverted T waves and isoelectric ST segments in leads II, III and aVF. Coronary angiography revealed that the study group had a higher incidence of significant right coronary artery obstruction and collateral circulation between the left coronary system and the posterior descending artery than did the control group (100 versus 25% and 73 versus 0%, respectively; p less than 0.01). There were no differences between the groups regarding left anterior descending and circumflex artery disease.(ABSTRACT TRUNCATED AT 250 WORDS)